This invention relates to an apparatus to attract and kill flies, specifically to a non-toxic, non-chemical electronic means for reducing the fly population in and around commercial facilities such as dairies, feed lots, poultry houses, and processing plants by applying a burst of high voltage oscillations to a set of or a grid of exposed parallel conductors. The flies are attracted to these exposed conductors by appealing to the flies natural instincts to breed an lay their eggs. The flies that contact the exposed conductors are killed and fall to the ground under the apparatus.
U.S. Pat. No. 5,325,624 issued to Richardson et al on Jul. 5,1994 discloses a non-toxic, non-chemical, non-polluting electronic apparatus to control the fly population within an animal or poultry enclosure which does not kill by electrocution or incineration but rather by destroying the nervous system of the fly with a short burst of high voltage oscillations that is applied to a set of parallel conductors. U.S. Pat. No. 5,979,107 issued to Richardson et al on Nov. 9, 1999 disclosed an improved means for obtaining and installing the parallel conductors that is also not limited to straight runs but can be installed in any pattern as long as the proper spacing between the conductors is maintained. Both of the above apparatus relied on the natural instincts of some species of flies to roost and are limited to permanent indoor applications.
Experience resulting from the widespread use of the above inventions has shown the need for an apparatus that will attract and kill blow flies, carrion flies, face flies, and other biting and pest flies as well as the common house flies. These other flies and biting insects are not attracted to a roosting site as are the common house flies and they generally populate outdoor areas rather than indoor facilities.
The electronic devices generally used as a means of eliminating insects near homes and gardens using blacklight or fluorescent lights as an attractant and a constant high voltage alternating current on the grid to kill the insects have been tried and proven to be ineffective for these applications. The insects that are of a concern to the commercial farmer and food processor are common house flies, blow flies, carrion flies, face flies, and other biting and pest flies. These flies are not attracted by the fluorescent or black lights used in the units that are intended primarily for mosquitoes and moths.
Devices called xe2x80x9cfly trapsxe2x80x9d using carrion or rotting mash as an attractant are available for commercial use. Their general configuration is one where the fly is attracted through a funnel trap arrangement into a bucket to collect the flies. The bucket must be cleaned out periodically and therefore maintenance of the units is high and in heavy fly infestations these units are easily overwhelmed.
U.S. Pat. No. 5,369,909 issued to Murphy on Dec. 6, 1994 places a set of parallel conductors on an electric fence and uses the high voltage pulse from an electronic fence charger and a ground rod as the electrical return path. The experience gained from many tests has proven this to not be an effective fly killing device. The high voltage pulse from a fence charger does not contain sufficient energy to kill flies and the ground return is not reliable as a low resistance conductor. A typical electronic fence charger produces very narrow pulses (1-2 usec) with an amplitude of 6-10 KV peak and a pulse repetition rate of about one pulse per second. The output energy content of these fence controllers is determined by the size of the capacitor in which the energy is stored and the voltage across the capacitor. The relationship is expressed mathematically as E=xc2xd C(Vxc3x97V) where E=energy in joules. A typical electronic fence charger will have a potential pulsed energy output of 0.5 to 10 joules. A standard electronic fence charger with the highest output energy will not kill flies on a conducting wire grid as defined herein. It tends to have the same effect on flies as it does on a cow or a horse, that is, the shock repels the animal and trains it to stay away from the device.
Another problem found in the attempts to use a standard electronic fence charger to supply the killing voltage to the grid network was the pulse repetition rate of about 1 per second does not allow sufficient time for the fly to land on the grid network or surrounding surfaces and approach the conducting grid. The repetition rate must be one every 2 to 4 seconds. Two seconds allows time for the flies to land and 4 seconds does not allow sufficient time for them to get to the holes to the attractant.
Extensive testing has found that a pulse width of 20 milliseconds or greater is required to supply sufficient energy to kill flies. As the pulse width is decreased below 20 milliseconds fewer and fewer flies will be killed and more just repelled. Greater than 80 milliseconds contains sufficient energy to cause ignition of some materials.
A typical electronic fence charger outputs a pulse of approximately 1 microsecond. To increase this pulse width from 1 microsecond to the required 20 milliseconds would require an unreasonably large capacitor. This capacitor would have to be in excess of 200,000 microfarads with an operating voltage capability of at least 600 VDC and would have to store over 10 to the 13th power (obviously impossible) joules.
The invention disclosed herein supplies a voltage burst to the grid network that is 8000 volts peak-to-peak with a duration of 60 milliseconds and a burst repetition rate of one burst every 2xc2xd seconds. This is a burst of 8000 V peak-to-peak oscillations and not an 8000 Volt peak pulse of energy as is outputted by electric fence chargers. This burst provides the maximum killing energy to effectively kill the flies but remains narrow enough and infrequent enough to be safe considering fire hazards as well as safety to humans and animals.
The use of a high impedance output transformer limits the output current and thus gives added safety to humans and animals but provides sufficient power to kill flies that contact the parallel conductors of the grid.
It is recognized by all concerned with the production of livestock or poultry and operators of dairies and food processing plants that control of the fly population is necessary to maintain animal health, keep the premises sanitary, and reduce complaints from workers and neighbors. The animals in these locations attract a great many flies that can lead to health related problems for the animals as well as complaints from surrounding residents. Dairies often move the livestock to different pastures at varying periods which means that the fly control apparatus must necessarily be moved from time to time to remain in proximity to the livestock and to maintain its effectiveness to control the fly population. Food processing plants have similar fly control problems and the chemicals available for control at these locations is very limited, expensive, and the use of them is continuously under attack by environmental and governmental groups. Whereas, the concepts disclosed in U.S. Pat. Nos. 5,325,624 and 5,979,107 provides only an attractive roosting site and kills the flies that land on the roosting means, the basic objective of this invention is to provide the most efficient attractant for the given environment and nature of the pests and provide an electronic means to kill the attracted flies and control their population whether indoors or outdoors.
The referenced patents use extremely long runs of highly conductive parallel wires as a roosting means (up to several thousand feet) hung throughout the livestock enclosure. The roosting means must be moisture resistant but need not be weather proof as they are always installed inside the livestock enclosure. An object of this invention is to disclose a new relocatable killing grid, hereafter referred to as the xe2x80x9cFly Towerxe2x80x9d, that contains an active attractant that represents a perfect breeding/laying means to attract all species of flies and kills the flies with a controlled burst of high voltage oscillations from an electronic control unit thus killing more flies and a broader range of fly species.
Another objective of this invention is to provide a simple non-toxic, non-chemical, effective, inexpensive fly population control apparatus that requires very little maintenance and can be effectively and safely used indoors or outdoors in all weather conditions.
Another objective is to provide a fly control apparatus that can be easily and quickly moved from one location to another to xe2x80x9cfollow the herdxe2x80x9d and thus be easily relocated to the problem areas.
Another objective is to provide an apparatus wherein several of the attracting and killing means can be operated from one electronic device.
Another objective is to provide means of attracting the flies that not only attracts and kills the common house fly but also will attract and kill blow flies, carrion flies, face flies, and other biting and pest flies.
Another objective of this invention is to reduce the labor necessary to install the fly killing system and also to reduce maintenance cost associated with previously disclosed systems.
Another objective of this invention is to disclose an inexpensive, effective electronic control unit that can be powered from a standard 12 volt battery for use in remote locations where 115 VAC power is not available.
Further objectives and advantages of this invention will become apparent from a consideration of the drawings and ensuing description.